Process of removing impurities from washed textiles



atente Apra 13, 1943 PROCESS OF REMO G URETEES FRQM WASH) TEXTEJES Erhart Welter, Dusseldort-nrath, Germany,

- assignor, by mesne assients, to The octer & Gamble Company, Cincinnati, filo, a corporation of Qhio No Drawing. Application June 24, 15939, Serial 2 Ciaims. (or. 252-143) This invention relates to a process for removing water insoluble soaps or precipitates from textiles which have been treated with those washing agents which form insoluble precipitates in hard water.

When textiles are cleansed in hard water, most washing agents leave a water-insoluble precipi tate which prevents thorough cleansing and dulls ferent agents may be judged from the ash content of several different types of washed fabrics. The degree of effectiveness of acetic, oxalic and sulfaminic acids in concentrations of five grams of acid per liter of treatment liquid when treating linens, mixed fabrics and chifions for a quarter of an hour to remove detrimental deposits is made clear.

the fibers. These precipitates, in some instances, may even cause permanent damage if they are Percent Percent Percent not thoroughly removed. Various partially sucgg g g ash after ash after figg g'g cessful methods have-been advanced for removwashing g ifl ag' i fff ggfif with amideing these precipitates. One of these methods acid acid $3 involves the use of dilute solutions of acids, such as baths containing acetic acid. 1 Linen a 2.1 17

crystallized acids have proved especially ad- Mixed fibers .10.3 7.5 2.3 0.12 vantageous for household use because they 00- cupy less space, are more easily stored and handled and are much more easily dosed than dilute acid solutions of varying concentration. Oxalic acid in crystalline form has been used for this P11113059.

It is an object of this invention to provide a highly effective method for removing detrimental water-insoluble precipitates from textiles involving the use of an inexpensive, readily available acid treating ae'ent.

In accordance with this invention, treatment baths acidulated with amidosulfonic acid or sulfaminic acid have proven surprisingly efiective in removing detrimental water-insoluble precipitates deposited upon textile in washing operations. Sulfaminic acid is easy to prepare, inexpensive, is readily available and may be used in the crystalline state or in aqueous solutions.

In the preparation of rinsing baths, the sulfaminic acid is preferably introduced as crystals either alone or in combination with inert water-soluble materials, such as salts. Since the acid is stable in aqueous solutions, it may be marketed in such solutions for introduction into rinsing baths without a material loss in efiectiveness.

The relative eficiency of the instant acid compound as compared withcompounds of the prior art may quickly be observed from the tests set" out below, wherein the effectiveness of the dit- The foregoing results clearly show the superiority of the processes and treatment baths for removing detrimental deposits resulting from washing operations when acidulation is produced through the use of sulfaminic acid.

The amount of sulfaminic acid required is not critical and may be varied in relation to the quantity of the deposits or hardness of the water.

Under one percent in the rinsing bath is slimcient.

It should be understood that the present invention is not limited to the specific compositions and processes herein set out, but that its scope is to be judged by the wording of the appended claims as interpreted in the light of the general tenor of the specification.

I claim:

l. The method of removing deleterious deposits from a textile material washed in hard water; which comprises rinsing said material in an aqueous rinsing bath a'cidulated with approximately .5% sulfaminic acid.

2. The method of removing deleterious deposits from textile materials washed in hard water, which comprises rinsing said materials in a rinsing bath comprising water and less than 1% sulfaminic acid.

ERHART WOLTER. 

